/Engine/Plugins/Editor/ObjectMixer/LightMixer/Source/LightMixer/Public/LightMixerObjectFilter.h
Return the basic actor types you want to be able to place using the Add button. Note that only subclasses ofAActorare supported and only those which have a registered factory. This includes most engine actor types.
virtual [TSet](API\Runtime\Core\Containers\TSet)< [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [AActor](API\Runtime\Engine\GameFramework\AActor) > > GetObjectClassesToPlace() const